<!DOCTYPE html>
<html>

<head>
    <meta charset="utf-8">
    <title>菜鸟教程(runoob.com)</title>
    <style>
        /* 这个例子演示了如何使用百分比值设置元素的高度。 */
        html {
            height: 100%;
        }

        body {
            height: 100%;
        }

        img.normal {
            height: auto;
        }

        img.big {
            height: 50%;
        }

        img.small {
            height: 10%;
        }
    </style>
</head>

<body>
    <img class="normal" src="images/logocss.gif" width="95" height="84" /><br>
    <img class="big" src="images/logocss.gif" width="95" height="84" /><br>
    <img class="small" src="images/logocss.gif" width="95" height="84" />
</body>

</html>